Pigment/frit mixtures

ABSTRACT

Frits or frit mixtures with pearlescent pigments for materials, such as ceramic glazes, which are stable above 1000° C.

An aspect of the invention is frits or frit mixtures with pearlescentpigments for ceramic glazes which are stable above 1000° C.

In general, decorative applications in ceramic glazes use mixtures ofpigments, for example effect pigments, and ceramic frits/frit mixtures.In particular, these are used for ceramic glazes in the high-temperaturerange above 1000° C., for example for

-   single-fired wall tiles at 1100-1200° C.,-   single-fired floor tiles at 1100-1250° C.,-   porcelain at 1100-1300° C., and double-fired at 1050-1080° C.

They are also employed, in particular, in the case of decorative tilesor porcelain. A problem occurs that the pigments, in particular therepresentatives from the class of the pearlescent pigments, generally donot survive the aggressive conditions consisting of oxidic melt (fritcomponents) and high temperatures during the firing process withoutdamage.

Efforts have therefore been made in the past to stabilise the effectpigments, in particular pearlescent pigments, by sheathing withinsulating protective layers for thermally and chemically extremelyhighly demanding applications of this type.

It is known from the prior art that a significant loss in tintingstrength and pearlescent effect must be expected on use of pearlescentpigments in ceramic glazes used in the region >1000° C. In order toprevent this, these pigments must either be encapsulated in additionalprotective layers, or alternatively the use of pearlescent pigments inthis high-temperature area of application is limited to ironoxide-coated pearlescent pigments in especially modified engobes orfluxes.

EP 220 509 A1 describes, for example, the stabilisation of pearlescentpigments by means of SnO₂ and/or CeO₂ layers.

EP 307 771 A1 discloses the encapsulation of pearlescent pigments withan Au-doped SnO₂ layer for a combination of stabilisation and noveldecorative effects. In order to achieve the desired stabilisation,substantial amounts of the oxide/oxide combinations mentioned have to beapplied in both cases. It has thus proved advantageous to apply theprotective coating in amounts of about 5-30% by weight, based on theentire pigment.

DE 39 32 424 C1 discloses pearlescent pigment/frit combinations with andwithout additional absorptive pigments. However, the use range of thepigmented glass frit is only a maximum of 700-900° C.

GB 2 096 592 A describes the use of pearlescent pigments in ceramicfluxes comprising frits. Neither the target firing temperature nor theparticular problems on use of pearlescent pigments at temperaturesof >1000° C. are discussed here.

U.S. Pat. No. 5,783,506 describes the use of TiO₂- or Fe₂O₃-coated micapigments in ceramic fluxes which are capable of “leafing”, i.e.formulations consisting of frit, dispersant, binder, mica andpearlescent pigment based on mica, of a defined viscosity. The inventionin this US patent consists in that the pearlescent pigments migrate tothe surface of the glaze (leafing) due to the addition of mica.

U.S. Pat. No. 4,353,991 discloses the use of pearlescent pigments havinga particle size of 1-200 μm in “fritted glass enamel” in a concentrationrange from 0.5 to 25.0% by weight, based on the weight of thefrit/pigment mixture. However, these mixtures can only be used attemperatures up to a maximum of 538-760° C.

EP 0 419 843 A1 describes the use of pearlescent pigments in a useconcentration of 5-20% by weight in a glass frit. The use temperature isgiven as 800-900° C. for rapid firing or 700-800° C. for standardfiring.

CN 101462895A discloses the use of 10-60% by weight of goldenpearlescent pigments in glazes at 1000-1200° C. The frit employed hereis composed of

-   SiO₂: 55˜80%-   Al₂O₃: 5˜20%-   CaO: 0.5-3%-   MgO: 0-2%-   Na₂O: 1˜5%-   K₂O: <5%-   B₂O₃: 3˜15%.

It is disadvantageous here that the use is restricted exclusively tospecific gold-coloured pearlescent pigments based on mica, with thelayer structure of the gold-coloured pearlescent pigments not beingdisclosed. The number and choice of colour of the pigments which can beemployed is thus very greatly restricted in CN 101462895A.

DE 198 59 420 A1 discloses modified engobes having a pearlescent effect.The coating of earthenware and ceramicware in order to improve (prime)the surface through fineness or colour is usually carried out usingengobes. The modified engobes achieve better adhesion of the engobe tothe fired or unfired tiles, earthenware and ceramicware. The engobecomprises a frit for the firing range 600-1200° C. and one or morepearlescent pigments.

The solutions known from the prior art, such as, for example, theencapsulation of the pigments, are complex in production, since afurther process step for application of the protective layer must becarried out in production. In addition, disadvantageous effects, suchas, for example, clouding of the glaze and colour changes in the pigmentor poorer control of the colour effect in the application medium, mayoccur, depending on the composition of the protective layer. The secondsolution—the use of pearlescent pigments with an iron oxide layer—is incolour terms very limited to the colour effects that can be achieved byiron oxide-coated pearlescent pigments.

An object of the invention was therefore to find a readily controllablecombination of frit and pearlescent pigment which is, in particular,reliable from an applicational point of view and is stable attemperatures above 1000° C. and at the same time results in optimalplane-parallel alignment of the pearlescent pigments in the glaze andthus significantly improves the colour effect of pearlescent pigmentswhen used for ceramic glazes in the high-temperature range, i.e. attemperatures >1000° C. Furthermore, the range of colours which can beemployed in accordance with the invention should be significantlyexpanded to include TiO₂ interference silver-white, TiO₂ interferencecolours (gold, copper, red, violet, blue, turquoise and green), and ironoxide interference colours in the gold, bronze, copper and red region.

Surprisingly, it has now been found that pearlescent pigments based onflake-form substrates in frit/pearlescent pigment combinations withAl₂O₃-rich frits, so-called “hard” frits, are particularly stable in theuse range of temperatures >1000° C., and particularly attractive andeasily controllable colour effects are thus achieved.

An aspect of the present invention therefore is a pearlescentpigment/frit mixture in which the proportion of pearlescent pigment inthe mixture is 5-95% by weight, based on the mixture, and the fritcomprises at least 5% of Al₂O₃.

The use of “hard” frits results in a significantly improvedplane-parallel alignment of the pearlescent pigments within the glazeand thus in an optimised optical effect of the glaze, in particular withrespect to colour and gloss. The optimised plane-parallel alignment ofthe pearlescent pigments is furthermore supported by the combinationaccording to the invention of pearlescent pigment and hard frit andfacilitates a high pigment use concentration of, for example, >30% byweight, preferably >50% by weight and in particular 60-95% by weight.Furthermore, the inventive pigment/frit mixture which is optimised forthe target temperature range in the application facilitates for the userreliable usability of the pearlescent pigments in ceramic glazes, which,owing to the colour constancy, is accompanied by easy adjustability ofthe colour effect.

The pearlescent pigment/frit mixture according to the inventionfurthermore enables the range of colours to be expanded to include TiO₂interference pigments having attractive silver-white and colourinterference shades, and by Fe₂O₃ interference pigments having masstones, gold, bronze, copper and red shades. Finally, this inventivecombination, which is optimised for the target temperature range in theapplication, facilitates for the user reliable usability of thesepigments.

If the proportion by weight of pigment in the pearlescent pigment/fritmixture is, for example, 5-95% by weight, preferably 20-85% by weightand in particular 30-80% by weight, based on the pigment/frit mixture,the pearlescent pigments in the so-called “hard” frit having an Al₂O₃content of ≥5% by weight, based on the frit, exhibit a pronounced highlyplane-parallel alignment of the individual pearlescent pigmentparticles.

In the case of a pre-specified layer thickness and comparable particlesizes, high pigmentation of the frit favours an approximatelyplane-parallel alignment, which results in a significantly greaterpearlescent effect. In the case of a lower pigment concentration, arandom distribution of the alignment is present, as shown in FIGS. 1 and2. In these two figures, which show sectional side views through apigmented frit layer before the firing operation, the particles of thefrit are represented as round or oval particles and the pearlescentpigments are represented as rods.

The highly plane-parallel alignment of the pearlescent pigments which isadvantageous for optimisation of the colour effect can furthermoreadditionally be favoured if the ratio of the thickness of thepearlescent pigment to the size of the frit particle is preferably onaverage in an least an order of 0.01-2, in particular 0.5-1.5 and veryparticularly 1. The frit particles here are generally in flake form,i.e. as flakes (defined by an aspect ratio=ratio of particle diameter toparticle thickness of ≥4:1), spherical, oval or irregularly shaped. Afactor for the alignment is the size in at least one dimension.

If, for example, the pearlescent pigment has a thickness of 700 nm, itshould preferably be mixed with frit particles which have the followingdimensions: flake-form frits having a thickness of 700 nm, sphericalfrits having a diameter of 700 nm or oval or irregularly shaped fritparticles having an average particle size of 700 nm.

Preferred dimensions of frit and pearlescent pigment are shown belowwith reference to some illustrative examples:

-   -   1) Pigment thickness: 800 nm, size of the frit particle in at        least one dimension 800 nm, ratio: 1    -   2) Pigment thickness: 800 nm, size of the frit particle in at        least one dimension 1600 nm, ratio: 0.5    -   3) Pigment thickness: 800 nm, size of the frit particle in at        least one dimension 400 nm, ratio: 2    -   4) Pigment thickness: 1600 nm, size of the frit particle in at        least one dimension 1600 nm, ratio: 1    -   5) Pigment thickness: 1600 nm, size of the frit particle in at        least one dimension 3200 nm, ratio: 0.5    -   6) Pigment thickness: 1600 nm, size of the frit particle in at        least one dimension 800 nm, ratio: 2.

At values greater than 2, no significant improvement in the alignment ofthe pigment particles is generally evident. The plane-parallel alignmentof the pearlescent pigments in the glaze, which is favourable for thedesired intense pearlescent effect, is less adversely affected, thesmaller the frit particles are on average in relation to the pigmentparticles, as depicted diagrammatically in FIGS. 3-5. In addition,flake-form frit particles generally have a very positive effect on theplane-parallel alignment of the likewise flake-form pearlescentpigments. In the figures, the oval or round particles represent the fritparticles, while the rods are the pearlescent pigments based onflake-form substrates.

The use of coarse frits, as depicted in FIG. 3, results in dealignment,while the use of a finer frit, i.e. the frit particles are smaller thanor approximately the same size as the pearlescent pigment particles inat least one dimension, which is depicted diagrammatically in FIGS. 4and 5, generally results in very good alignment of the pearlescentpigments. In the case of finer frits, the frit particles preferably havedimensions in the order of the pigment thicknesses, i.e. 10-2,000 nm andin particular 50-1500 nm.

As already mentioned, the optimum plane-parallel alignment of thepearlescent pigments is supported by the combination according to theinvention of pearlescent pigment and hard frit, in that this supports aparticularly high pigment use concentration of, for example, >30% byweight. The effect generally increases successively from ≥30% by weight,via ≥50% by weight to ≥90% by weight with increasing pigmentconcentration and is only limited by the onset of chalking of thepigment from the glaze if the frit proportion is too low.

Besides the optimum alignment of the individual pearlescent pigmentparticles, the temperature stability and the stability to chemicallyhighly reactive media (the frit melt) furthermore play a crucial rolefor use of the pigment/frit mixture. The use of Al₂O₃-containing fritssignificantly increases the temperature stability. The Al₂O₃ content inthe frit is preferably ≥5% by weight, in particular ≥7% by weight andvery particularly preferably ≥9% by weight, based on the frit.

The commercially available frits are usually composed of constituentswhich are usual in frits, such as, for example, Al₂O₃, SiO₂, B₂O₃, TiO₂,ZrO₂, Sb₂O₃, P₂O₅, Fe₂O₃, alkali metal oxides and alkaline-earth metaloxides.

Preferred frits comprise

-   -   (Na₂O+K₂O+Li₂O)<10% by weight    -   Al₂O₃>5% by weight    -   SiO₂>50% by weight        where the total proportion of all constituents of the frit is        100%.

Suitable frits having a content of Al₂O₃ of ≥5% by weight, based on thefrit, are commercially available. As an example, without restricting thenumber of frits/fluxes that can be employed, mention may be made of FLUX101911, FLUX DSDC101915, frit DA4193 or frit DA4113 from Ferro.

The temperature stability can—purely optionally—furthermore be increasedif the pigment/frit mixture according to the invention is employed on anengobe which has previously been applied to the workpiece (body).Engobes are mixtures which may comprise molten ceramic frits, ceramicraw materials or minerals, glass or crockery porcelain powder and/orinorganic opacifiers. These engobes can be applied in ground form asaqueous suspensions (slips) to ceramic substrates in order to mask thehue of the substrate and to improve processing of the subsequentcoatings or layers, without at the same time adversely affecting theadhesion or surface quality of the finished product. The use of theengobe increases the use temperature further by 40-80 K, for examplefrom 1120-1160° C. to 1180-1200° C.

The pearlescent pigment/frit mixture according to the invention can,however, preferably also be fired directly onto the workpiece, and thenexhibits highly chromatic colour effects in the high target temperaturerange, i.e. at 1150-1200° C. The additional advantage thus arises thatthe colour pattern can be applied to the workpiece using only a singleprinting step, whereas a second printing step would be necessary for theengobe.

Finally, particularly high temperature stability is generally achievedif use is made of pearlescent pigments based on flake-form substrateswhich are stable at high temperatures. Examples which may be mentionedhere are: corundum—Al₂O₃, carborundum—SiC, boron nitride—BN, graphiteand haematite—Fe₂O₃.

It is also possible to employ mixtures of different substrates ormixtures of the same substrates having different particle sizes. Thesubstrates can be mixed with one another in any weight ratio. 10:1 to1:10 mixtures are preferably employed, in particular 1:1 mixtures.Particular preference is given to substrate mixtures consisting ofsubstrate flakes having different particle sizes, in particular mixturesof S fraction (10-200 μm), N fraction (10-60 μm) and F fraction (5-25μm), but also of F fraction (5-25 μm) and M fraction (1-15 μm).

The size of the base substrates is not crucial per se and can be matchedto the particular application and desired target effect/target texture:for example, satin or highly glittering.

In general, the flake-form substrates, also referred to as flakesubstrates, preferably have a thickness of 0.05-5 μm, more preferably0.1-2 μm, in particular 0.1-1 μm. The size in the two other dimensionsis preferably 1-500 μm, more preferably 1-250 μm and in particular 1-60μm.

The thickness of at least one individual layer on the base substrate ofthe pearlescent pigment is essential for the optical properties of thepigment, as already described in numerous patents and patentapplications, for example in DE 14 67 468, DE 19 59 988, DE 20 09 566,DE 22 14 545, DE 22 15 191, DE 22 44 298, DE 23 13 331, DE 25 22 572, DE31 37 808, DE 31 37 809, DE 31 51 343, DE 31 51 354, DE 31 51 355, DE 3211 602, DE 32 35 017 or also in further patent documents and otherpublications known to the person skilled in the art.

The pigment must have at least one optically active layer, preferably ahigh-refractive-index layer (for example TiO₂, Fe₂O₃, SnO₂, etc.).High-refractive-index layers here are taken to mean all layers whichhave a refractive index of n ≥1.8, preferably of n ≥2.0.

Use is very particularly preferably made in the pearlescent pigment/fritmixtures according to the invention of pearlescent pigments based onsynthetic mica flakes, natural mica flakes and very particularlypreferably based on high-temperature-resistant flakes, such as, forexample, Al₂O₃, SiC, B₄C, BN, graphite, TiO₂ and Fe₂O₃ flakes.

Suitable substrate flakes for the pearlescent pigments may be doped orundoped. If they are doped, the doping is preferably Al, N, B, Ti, Zr,Si, In, Sn or Zn or mixtures thereof. Furthermore, further ions from thegroup of the transition metals (V, Cr, Mn, Fe, Co, Ni, Cu, Y, Nb, Mo,Hf, Ta, W) and ions from the group of the lanthanides may serve asdopants.

In the case of Al₂O₃, the substrate is preferably undoped or doped withTiO₂, ZrO₂ or ZnO. The Al₂O₃ flakes are preferably corundum. SuitableAl₂O₃ flakes are preferably doped or undoped α-Al₂O₃ flakes, inparticular TiO₂-doped α-Al₂O₃ flakes. If the substrate is doped, theproportion of the doping is preferably 0.01-5.00% by weight, inparticular 0.10-3.00% by weight, based on the substrate.

Suitable Al₂O₃ flakes preferably have an equivalence diameterdistribution according to which 90% of the particles are in the range5-45 μm, preferably 5-40 μm.

The D₅₀ values of the Al₂O₃ flakes are preferably in the range 15-30 μm,very particularly preferably in the range from 15-25 μm.

The D₁₀ values are preferably in the range 5-15 μm, very particularlypreferably in the range 6-10 μm.

Throughout the application, the D₁₀, D₅₀ and D₉₀ values are determinedusing a Malvern MS 2000.

The thickness of the Al₂O₃ flakes is preferably 50-1200 nm, morepreferably 150-800 nm and in particular 200-450 nm.

In a very particularly preferred embodiment, the thickness of the Al₂O₃flakes is <500 nm, preferably 150-450 nm and in particular 150-400 nm.

The aspect ratio (diameter/thickness ratio) of the Al₂O₃ flakes ispreferably 10-1000, in particular 50-500.

In a further preferred embodiment, the aspect ratio of the Al₂O₃ flakesis 30-200, in particular 50-150.

In a preferred embodiment, the flake-form substrate is coated with oneor more transparent, semi-transparent and/or opaque layers comprisingmetal oxides, metal oxide hydrates, metal silicates, metal suboxides,metals, metal fluorides, metal nitrides, metal oxynitrides or mixturesof these materials. The metal oxide, metal oxide hydrate, metalsilicate, metal suboxide, metal, metal fluoride, metal nitride or metaloxynitride layers or the mixtures thereof can have a low refractiveindex (refractive index <1.8) or a high refractive index (refractiveindex ≥1.8). Suitable metal oxides and metal oxide hydrates are allmetal oxides or metal oxide hydrates known to the person skilled in theart, such as, for example, aluminium oxide, aluminium oxide hydrate,silicon oxide, silicon oxide hydrate, iron oxide, tin oxide, ceriumoxide, zinc oxide, zirconium oxide, chromium oxide, zirconium silicateZrSiO₄, mullite, titanium oxide, in particular titanium dioxide,titanium oxide hydrate and mixtures thereof, such as, for example,illmenite or pseudobrookite. Metal suboxides which can be employed are,for example, the titanium suboxides (for example Ti₂O₃ or γ-Ti₃O₅).Suitable metal silicates are aluminium silicate, Mg silicate, Casilicate or Ba silicate; mixed alkaline-earth metal silicates, such as,for example, Ca/Mg silicate, Zr silicate or mixtures of the saidsilicates. Suitable metals are, for example, chromium, aluminium,nickel, silver, gold, titanium, copper or alloys, and a suitable metalfluoride is, for example, magnesium fluoride. Metal nitrides or metaloxynitrides which can be employed are, for example, the nitrides oroxynitrides of the metals titanium, zirconium and/or tantalum. Metaloxide, metal, metal fluoride and/or metal oxide hydrate layers and veryparticularly preferably metal oxide and/or metal oxide hydrate layersare preferably applied to the support. Furthermore, multilayeredstructures comprising high- and low-refractive-index metal oxide, metaloxide hydrate, metal or metal fluoride layers may also be present, withhigh- and low-refractive-index layers preferably alternating. Particularpreference is given to layer packages comprising a high-refractive-indexlayer and a low-refractive-index layer, where one or more of these layerpackages may be applied to the support. The sequence of the high- andlow-refractive-index layers here can be matched to the support in orderto incorporate the support into the multilayered structure. In a furtherembodiment, the metal oxide, metal silicate, metal oxide hydrate, metalsuboxide, metal, metal fluoride, metal nitride or metal oxynitridelayers may be mixed or doped with colorants or other elements. Suitablecolorants or other elements are, for example, inorganic colouredpigments, such as coloured metal oxides, for example magnetite,chromium(III) oxide or coloured pigments, such as, for example,Thenard's Blue (a Co/AI spinel) or elements, such as, for example,yttrium or antimony, and generally pigments from the structural class ofthe perovskites, pyrochlores, rutiles and spinels. Pearlescent pigmentscomprising these layers exhibit great colour variety with respect totheir mass tone and may in many cases exhibit an angle-dependent changein colour (colour flop) due to interference.

In a preferred embodiment, the outer layer on the support is ahigh-refractive-index metal oxide. This outer layer may additionally beon the above-mentioned layer packages or, in the case ofhigh-refractive-index supports, may be part of a layer package andconsist, for example, of TiO₂, titanium suboxides, Fe₂O₃, SnO₂, ZnO,ZrO₂, Ce₂O₃, CoO, Co₃O₄, V₂O₅, Cr₂O₃ and/or mixtures thereof, such as,for example, ilmenite or pseudobrookite.

The thickness of the metal oxide, metal oxide hydrate, metal silicate,metal suboxide, metal, metal fluoride, metal nitride or metal oxynitridelayers or a mixture thereof is preferably 3 to 300 nm and, in the caseof the metal oxide, metal oxide hydrate, metal suboxide, metal fluoride,metal nitride or metal oxynitride layers or a mixture thereof, morepreferably 20 to 200 nm. The thickness of the metal layers is preferably4 to 50 nm.

The optical layer preferably consists of TiO₂, ZrO₂, Fe₂O₃, Fe₃O₄, SnO₂,ZnO, or mixtures or combinations thereof. The layer may be undoped ordoped. Suitable dopants are, for example, alkaline-earth metals orcompounds thereof, in particular calcium and magnesium. The dopingproportion is generally a maximum of 5% by weight, based on therespective layer.

The optical layer is particularly preferably a TiO₂ layer, an Fe₂O₃layer, a TiO₂/Fe₂O₃ mixed layer, a pseudobrookite layer (Fe₂TiO₅) or acombination of these layers in a multilayered system, such as, forexample, TiO₂—SiO₂—TiO₂ or Fe₂O₃—SiO₂—Fe₂O₃.

The titanium dioxide may be present in the high-refractive-index coatingin the rutile or anatase modification, preferably in the form of rutile.The processes for the preparation of rutile are described, for example,in the prior art in U.S. Pat. Nos. 5,433,779, 4,038,099, 6,626,989, DE25 22 572 C2 and EP 0 271 767 B1. A thin tin oxide layer (<10 nm), whichserves as additive in order to convert the TiO₂ into rutile, ispreferably applied to the substrate flakes before the TiO₂precipitation.

The thickness of the optically active layer is preferably in each case30 to 350 nm, in particular 50 to 250 nm.

Pearlescent pigments based on flake-form substrates which areparticularly preferred for the pigment/frit mixture according to theinvention are indicated below:

-   substrate flake+TiO₂-   substrate flake+Fe₂O₃-   substrate flake+Fe₃O₄-   substrate flake+TiO₂/Fe₂O₃-   substrate flake+FeTiO₃-   substrate flake+Fe₂TiO₅-   substrate flake+ZrO₂-   substrate flake+ZnO-   substrate flake+SnO₂-   substrate flake+Cr₂O₃-   substrate flake+Ce₂O₃-   substrate flake+TiO_(x) (reduced), where x=1.50-1.95-   substrate flake+TiO₂+Fe₂O₃-   substrate flake+TiO₂+Fe₃O₄-   substrate flake+Fe₂O₃+TiO₂-   substrate flake+TiO₂+SiO₂+TiO₂-   substrate flake+TiO₂+SnO₂+TiO₂-   substrate flake+TiO₂+Al₂O₃+TiO₂-   substrate flake+Fe₂O₃+SiO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+SiO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+SiO₂+TiO₂/Fe₂O₃-   substrate flake+TiO₂/Fe₂O₃+SiO₂+TiO₂+TiO₂/Fe₂O₃-   substrate flake+TiO₂+SiO₂+TiO₂/Fe₂O₃-   substrate flake+TiO₂+SiO₂-   substrate flake+TiO₂+Al₂O₃-   substrate flake+TiO₂+MgO×SiO₂+TiO₂-   substrate flake+Fe₂O₃+MgO×SiO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂/Fe₂O₃-   substrate flake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂+TiO₂/Fe₂O₃-   substrate flake+TiO₂+MgO×SiO₂+TiO₂/Fe₂O₃-   substrate flake+SnO₂+TiO₂+SiO₂+SnO₂+TiO₂-   substrate flake+SnO₂+TiO₂+SnO₂+TiO₂-   substrate flake+SnO₂+TiO₂+Fe₂O₃+SiO₂+SnO₂+TiO₂+Fe₂O₃-   substrate flake+Fe₂O₃+SnO₂+TiO₂-   substrate flake+Fe₂O₃+SnO₂+Fe₂O₃-   substrate flake+TiO₂+SnO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+SnO₂+TiO₂-   substrate flake+TiO₂/Fe₂O₃+SnO₂+TiO₂/Fe₂O₃-   substrate flake+SnO₂+TiO₂+Fe₂O₃+SnO₂+TiO₂+Fe₂O₃.-   substrate flake+Fe₂TiO₅+SnO₂+Fe₂TiO₅-   substrate flake+Fe₂TiO₅+SiO₂+Fe₂TiO₅

In a further preferred embodiment, a first low-refractive-index layer isfirstly applied to the substrate flake. Low-refractive-index layer inthis application is taken to mean a layer which has a refractive indexof <1.8.

The low-refractive-index layer on the substrate is preferably selectedfrom the group Al₂O₃, SiO₂, zirconium silicate ZrSiO₄, mullite3Al₂O₃×2SiO₂ or 2Al₂O₃×SiO₂ (sintered or fused mullite) oralkaline-earth metal silicate (MSiO₃, where M=Mg²⁺, Ca²⁺, Sr²⁺ or Ba²⁺,or M₂Si₃O₈, where M=Mg²⁺, Ca²⁺, Sr²⁺ or Ba²⁺).

Preferred pigments having a low-refractive-index layer (LRL) on thesubstrate surface are distinguished by the following structures:

-   substrate flake+LRL+TiO₂-   substrate flake+LRL+Fe₂O₃-   substrate flake+LRL+Fe₃O₄-   substrate flake+LRL+TiO₂/Fe₂O₃-   substrate flake+LRL+FeTiO₃-   substrate flake+LRL+Fe₂TiO₅-   substrate flake+LRL+ZrO₂-   substrate flake+LRL+ZnO-   substrate flake+LRL+SnO₂-   substrate flake+LRL+Cr₂O₃-   substrate flake+LRL+Ce₂O₃-   substrate flake+LRL+TiO_(x) (reduced), where x=1.50-1.95-   substrate flake+LRL+TiO₂+Fe₂O₃-   substrate flake+LRL+TiO₂+Fe₃O₄-   substrate flake+LRL+Fe₂O₃+TiO₂-   substrate flake+LRL+TiO₂+SiO₂+TiO₂-   substrate flake+LRL+TiO₂+SnO₂+TiO₂-   substrate flake+LRL+TiO₂+Al₂O₃+TiO₂-   substrate flake+LRL+Fe₂O₃+SiO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+TiO₂+SiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+TiO₂+SiO₂-   substrate flake+LRL+TiO₂+Al₂O₃-   substrate flake+LRL+TiO₂+MgO×SiO₂+TiO₂-   substrate flake+LRL+Fe₂O₃+MgO×SiO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+TiO₂+MgO×SiO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+SnO₂+TiO₂+SiO₂+SnO₂+TiO₂-   substrate flake+LRL+SnO₂+TiO₂+SnO₂+TiO₂-   substrate flake+LRL+SnO₂+TiO₂+Fe₂O₃+SiO₂+SnO₂+TiO₂+Fe₂O₃-   substrate flake+LRL+Fe₂O₃+SnO₂+TiO₂-   substrate flake+LRL+Fe₂O₃+SnO₂+Fe₂O₃-   substrate flake+LRL+TiO₂+SnO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+SnO₂+TiO₂-   substrate flake+LRL+TiO₂/Fe₂O₃+SnO₂+TiO₂/Fe₂O₃-   substrate flake+LRL+SnO₂+TiO₂+Fe₂O₃+SnO₂+TiO₂+Fe₂O₃-   substrate flake+LRL+Fe₂TiO₅+SnO₂+Fe₂TiO₅-   substrate flake+LRL+Fe₂TiO₅+SiO₂+Fe₂TiO₅

It is also possible to use different pearlescent pigments as a mixturein the pearlescent pigment/frit mixture according to the invention.Preferably, only one type of pearlescent pigment is employed.

Layer or coating in this application is taken to mean the completecovering of the flake-form substrate.

The pearlescent pigments can be prepared relatively easily. The coveringof substrate flakes is preferably carried out by wet-chemical methods,where the wet-chemical coating methods developed for the preparation ofpearlescent pigments can be used. Methods of this type are described,for example, in DE 14 67 468, DE 19 59 988, DE 20 09 566, DE 22 14 545,DE 22 15 191, DE 22 44 298, DE 23 13 331, DE 25 22 572, DE 31 37 808, DE31 37 809, DE 31 51 343, DE 31 51 354, DE 31 51 355, DE 32 11 602, DE 3235 017 or also in further patent documents and other publications knownto the person skilled in the art.

Furthermore, the coating of the substrates can also be carried out bygas-phase coating in a fluidised-bed reactor, where, for example, theprocesses proposed for the preparation of pearlescent pigments in EP 0045 851 A1 and EP 0 106 235 A1 can be used correspondingly.

In the case of wet coating, the substrate particles are suspended inwater, and one or more soluble metal salts are added at a pH which issuitable for hydrolysis, which is selected so that the metal oxides ormetal oxide hydrates are precipitated directly onto the flakes withoutsecondary precipitations occurring. The pH is usually kept constant bysimultaneous metered addition of a base or acid. The pigments aresubsequently separated off, washed and dried and optionally calcined,where the calcination temperature can be optimised with respect to thecoating present in each case. In general, the calcination temperaturesare between 250 and 1000° C., preferably between 350 and 900° C. Ifdesired, the pigments can be separated off after application ofindividual coatings, dried and optionally calcined and then resuspendedfor precipitation of the further layers.

If, for example, a TiO₂ or TiO₂/Fe₂O₃ layer is to be reduced, thereduction of the finished pearlescent pigment is preferably carried outafter drying by subsequently calcining the pigment at 500 to 1200° C.,preferably at 500-1000° C., in particular at 500-800° C., for 0.5-5 h,preferably for 0.5-2 h, under reducing conditions, preferably underforming gas (N₂/H₂). On use of pigments which have been calcined underreducing conditions in the glaze, however, it has proven helpfullikewise to select reducing conditions under the firing conditions forthe workpiece to be glazed.

In order to improve the wettability and/or compatibility with theprinting medium, it is frequently preferred, depending on the area ofapplication, to subject the finished pearlescent pigment to inorganic ororganic post-coating or post-treatment. Suitable post-coatings orpost-treatments are, for example, the processes described in DE patent22 15 191, DE-A 31 51 354, DE-A 32 35 017 or DE-A 33 34 598. Thispost-coating simplifies handling of the pigment, in particularincorporation into various media. In order to improve the wettability,dispersibility and/or compatibility with the application media,functional coatings comprising organic or combined organic/inorganicpost-coatings may be possible, for example with silanes, as described,for example, in DE 10348174, EP 0090259, EP 0 342 533, EP 0 632 109, EP0 888 410, EP 0 634 459, EP 1 203795, WO 94/01498, WO 96/32446, WO99/57204, WO 2004/092284, U.S. Pat. Nos. 5,759,255, 5,571,851, WO01/92425 or in J. J. Ponjeé, Philips Technical Review, Vol. 44, No. 3,81 ff. and P. H. Harding J. C. Berg, J. Adhesion Sci. Technol. Vol. 11No. 4, pp. 471-493. The post-coating merely comprises a proportion byweight of preferably 0.1 to 5% by weight, more preferably 0.5 to 3% byweight, based on the pearlescent pigment.

In a particular embodiment of the invention, the pearlescent pigmentsare hydrophobically or amphiphilically post-coated, which, onapplication via printing pastes, results in the advantage of morehomogeneous distribution in the print medium and thus more homogeneouscolour distribution on the workpiece.

The pearlescent pigment/frit mixture according to the invention expandsthe range of colours of pigmented ceramic glazes on fired or unfiredbricks, floor and wall tiles for indoor or outdoor use, sanitaryceramics, such as bathtubs, washbasins and toilet pans, porcelaincrockery, earthenware and ceramicware by attractive interference colours(silver, gold, bronze, copper, red, violet, blue, turquoise, green), andwith so-called mass tone pearlescent pigments, which are distinguishedby a combination of interference and absorption colour, in particular inthe region of gold, brass, bronze, copper, red and green shades. Itfurthermore also facilitates entirely novel colour effects, such asviewing angle-dependent so-called colour flop effects. The choice of thepearlescent pigment furthermore facilitates novel optical effects, suchas sparkle/glitter effects and coarse or fine structures.

The invention also relates to the use of the pearlescent pigment/fritmixture according to the invention for ceramic glazes on fired orunfired bricks, floor and wall tiles for indoor or outdoor use, sanitaryceramics, porcelain, earthenware and ceramicware.

The invention thus also relates to formulations comprising thepearlescent pigment/frit mixture according to the invention.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The preceding preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

In the foregoing and in the examples, all temperatures are set forthuncorrected in degrees Celsius and, all parts and percentages are byweight, unless otherwise indicated.

The entire disclosures of all applications, patents and publications,cited herein and of corresponding German application No. 102015013400,filed Oct. 19, 2015, are incorporated by reference herein.

The following examples are intended to explain the invention, butwithout limiting it.

EXAMPLES

The preparation and characterisation of a pigment/frit mixture accordingto the invention is divided into four steps:

1) Preparation of the Printing Paste:

For the preparation of fine colour grids and relief-like prints onceramic substrates by means of ceramic colours, use is made of screenprinting oils, which prevent running of the colour pastes after printingand give rise to prints with sharp contours. To this end, use is made ofadditives for the known binders, which consist of finely divided naturaland synthetic waxes and/or of finely divided inorganic silicate oroxidic substances which are capable of incorporation into the silicatestructure of the flux during firing. The pearlescent pigment with thecorresponding amount of frit and the print medium (screen printing oil221-ME and Screenprint Bulk 803035 MR—both commercially availableproducts from Ferro—were employed in the examples) are weighed out andhomogenised for a series of experiments (see Table 1).

The effect pigment according to Examples 1 to 275 is weighed out andhomogenised with the corresponding amount of frit of the followingcomposition:

Frit CaO Na₂O K₂O BaO Al₂O₃ SiO₂ B₂O₃ % by wt. 9.7 5.2 1.1 1.3 10.1 69.63.0

The weight of the corresponding raw materials, i.e. pearlescent pigment,frit and printing oil, for paste preparation is shown in the followingtable:

TABLE 1 W_(pig) in W_(pig) in Example Printing Pasting the the No.Pearlescent pigment Frit oil ratio solid paste 1 1.5 g Xirallic ©Crystal 3.5 g 7.0 g 10:14 30.00 12.50 Silver (Merck KGaA) 2 1.0 gXirallic © Crystal 3.5 g 7.0 g  10:15.6 22.22 8.70 Silver (Merck KGaA) 30.8 g Xirallic © Crystal 3.5 g 7.0 g  10:16.3 18.60 7.08 Silver (MerckKGaA) 4 0.6 g Xirallic © Crystal 3.5 g 7.0 g  10:17.1 14.63 5.41 Silver(Merck KGaA) 5 1.5 g Xirallic © Crystal 3.5 g 9.0 g 10:18 30.00 10.71Silver (Merck KGaA) 6 1.0 g Xirallic © Crystal 3.5 g 9.0 g 10:20 22.227.41 Silver (Merck KGaA) 7 0.8 g Xirallic © Crystal 3.5 g 9.0 g  10:20.918.60 6.02 Silver (Merck KGaA) 8 0.6 g Xirallic © Crystal 3.5 g 9.0 g10:22 14.63 4.58 Silver (Merck KGaA) 9 1.5 g Xirallic © Crystal 2.0 g7.0 g 10:20 42.86 14.29 Silver (Merck KGaA) 10 1.5 g Xirallic © Crystal1.5 g 7.0 g  10:23.3 50.00 15.00 Silver (Merck KGaA) 11 1.5 g Xirallic ©Crystal 1.0 g 7.0 g 10:28 60.00 15.79 Silver (Merck KGaA) 12 1.5 gXirallic © Crystal 0.5 g 7.0 g 10:35 75.00 16.67 Silver (Merck KGaA) 135.0 g Xirallic © Crystal 0.0 g 7.0 g 10:14 100.00 41.67 Silver (MerckKGaA) 14 2.0 g Xirallic © Crystal 3.0 g 7.0 g 10:14 40.00 16.67 Silver(Merck KGaA) 15 3.8 g Xirallic © Crystal 1.2 g 7.0 g 10:14 76.00 31.67Silver (Merck KGaA) 16 4.3 g Xirallic © Crystal 0.7 g 7.0 g 10:14 86.0035.83 Silver (Merck KGaA) 17 4.5 g Xirallic © Crystal 0.5 g 7.0 g 10:1490.00 37.50 Silver (Merck KGaA) 18 4.8 g Xirallic © Crystal 0.2 g 7.0 g10:14 96.00 40.00 Silver (Merck KGaA) 19 4.9 g Xirallic © Crystal 0.1 g7.0 g 10:14 98.00 40.83 Silver (Merck KGaA) 20 1.5 g Iriodin © 103 3.5 g7.0 g 10:14 30.00 12.50 (Merck KGaA) 21 1.0 g Iriodin © 103 3.5 g 7.0 g 10:15.6 22.22 8.70 (Merck KGaA) 22 0.8 g Iriodin © 103 3.5 g 7.0 g 10:16.3 18.60 7.08 (Merck KGaA) 23 0.6 g Iriodin © 103 3.5 g 7.0 g 10:17.1 14.63 5.41 (Merck KGaA) 24 1.5 g Iriodin © 103 3.5 g 9.0 g10:18 30.00 10.71 (Merck KGaA) 25 1.0 g Iriodin © 103 3.5 g 9.0 g 10:2022.22 7.41 (Merck KGaA) 26 0.8 g Iriodin © 103 3.5 g 9.0 g  10:20.918.60 6.02 (Merck KGaA) 27 0.6 g Iriodin © 103 3.5 g 9.0 g 10:22 14.634.58 (Merck KGaA) 28 1.5 g Iriodin © 103 2.0 g 7.0 g 10:20 42.86 14.29(Merck KGaA) 29 1.5 g Iriodin © 103 1.5 g 7.0 g  10:23.3 50.00 15.00(Merck KGaA) 30 1.5 g Iriodin © 103 1.0 g 7.0 g 10:28 60.00 15.79 (MerckKGaA) 31 1.5 g Iriodin © 103 0.5 g 7.0 g 10:35 75.00 16.67 (Merck KGaA)32 5.0 g Iriodin © 103 0.0 g 7.0 g 10:14 100.0 41.67 (Merck KGaA) 33 2.0g Iriodin © 103 3.0 g 7.0 g 10:14 40.00 16.67 (Merck KGaA) 34 3.8 gIriodin © 103 1.2 g 7.0 g 10:14 76.00 31.67 (Merck KGaA) 35 4.3 gIriodin © 103 0.7 g 7.0 g 10:14 86.00 35.83 (Merck KGaA) 36 4.5 gIriodin © 103 0.5 g 7.0 g 10:14 90.00 37.50 (Merck KGaA) 37 4.8 gIriodin © 103 0.2 g 7.0 g 10:14 96.00 40.00 (Merck KGaA) 38 4.9 gIriodin © 103 0.1 g 7.0 g 10:14 98.00 40.83 (Merck KGaA) 39 1.5 gIriodin © 305 3.5 g 7.0 g 10:14 30.00 12.50 (Merck KGaA) 40 1.0 gIriodin © 305 3.5 g 7.0 g  10:15.6 22.22 8.70 (Merck KGaA) 41 0.8 gIriodin © 305 3.5 g 7.0 g  10:16.3 18.60 7.08 (Merck KGaA) 42 0.6 gIriodin © 305 3.5 g 7.0 g  10:17.1 14.63 5.41 (Merck KGaA) 43 1.5 gIriodin © 305 3.5 g 9.0 g 10:18 30.00 10.71 (Merck KGaA) 44 1.0 gIriodin © 305 3.5 g 9.0 g 10:20 22.22 7.41 (Merck KGaA) 45 0.8 gIriodin © 305 3.5 g 9.0 g  10:20.9 18.60 6.02 (Merck KGaA) 46 0.6 gIriodin © 305 3.5 g 9.0 g 10:22 14.63 4.58 (Merck KGaA) 47 1.5 gIriodin © 305 2.0 g 7.0 g 10:20 42.86 14.29 (Merck KGaA) 48 1.5 gIriodin © 305 1.5 g 7.0 g  10:23.3 50.00 15.00 (Merck KGaA) 49 1.5 gIriodin © 305 1.0 g 7.0 g 10:28 60.00 15.79 (Merck KGaA) 50 1.5 gIriodin © 305 0.5 g 7.0 g 10:35 75.00 16.67 (Merck KGaA) 51 5.0 gIriodin © 305 0.0 g 7.0 g 10:14 100.0 41.67 (Merck KGaA) 52 2.0 gIriodin © 305 3.0 g 7.0 g 10:14 40.00 16.67 (Merck KGaA) 53 3.8 gIriodin © 305 1.2 g 7.0 g 10:14 76.00 31.67 (Merck KGaA) 54 4.3 gIriodin © 305 0.7 g 7.0 g 10:14 86.00 35.83 (Merck KGaA) 55 4.5 gIriodin © 305 0.5 g 7.0 g 10:14 90.00 37.50 (Merck KGaA) 56 4.8 gIriodin © 305 0.2 g 7.0 g 10:14 96.00 40.00 (Merck KGaA) 57 4.9 gIriodin © 305 0.1 g 7.0 g 10:14 98.00 40.83 (Merck KGaA) 58 1.5 gIriodin © 4504 3.5 g 7.0 g 10:14 30.00 12.50 Lava Red (Merck KGaA) 591.0 g Iriodin © 4504 3.5 g 7.0 g  10:15.6 22.22 8.70 Lava Red (MerckKGaA) 60 0.8 g Iriodin © 4504 3.5 g 7.0 g  10:16.3 18.60 7.08 Lava Red(Merck KGaA) 61 0.6 g Iriodin © 4504 3.5 g 7.0 g  10:17.1 14.63 5.41Lava Red (Merck KGaA) 62 1.5 g Iriodin © 4504 3.5 g 9.0 g 10:18 30.0010.71 Lava Red (Merck KGaA) 63 1.0 g Iriodin © 4504 3.5 g 9.0 g 10:2022.22 7.41 Lava Red (Merck KGaA) 64 0.8 g Iriodin © 4504 3.5 g 9.0 g 10:20.9 18.60 6.02 Lava Red (Merck KGaA) 65 0.6 g Iriodin © 4504 3.5 g9.0 g 10:22 14.63 4.58 Lava Red (Merck KGaA) 66 1.5 g Iriodin © 4504 2.0g 7.0 g 10:20 42.86 14.29 Lava Red (Merck KGaA) 67 1.5 g Iriodin © 45041.5 g 7.0 g  10:23.3 50.00 15.00 Lava Red (Merck KGaA) 68 1.5 gIriodin © 4504 1.0 g 7.0 g 10:28 60.00 15.79 Lava Red (Merck KGaA) 691.5 g Iriodin © 4504 0.5 g 7.0 g 10:35 75.00 16.67 Lava Red (Merck KGaA)70 5.0 g Iriodin © 4504 0.0 g 7.0 g 10:14 100.00 41.67 Lava Red (MerckKGaA) 71 2.0 g Iriodin © 4504 3.0 g 7.0 g 10:14 40.00 16.67 Lava Red(Merck KGaA) 72 3.8 g Iriodin © 4504 1.2 g 7.0 g 10:14 76.00 31.67 LavaRed (Merck KGaA) 73 4.3 g Iriodin © 4504 0.7 g 7.0 g 10:14 86.00 35.83Lava Red (Merck KGaA) 74 4.5 g Iriodin © 4504 0.5 g 7.0 g 10:14 90.0037.50 Lava Red (Merck KGaA) 75 4.5 g Iriodin © 4504 0.2 g 7.0 g 10:1496.00 40.00 Lava Red (Merck KGaA) 76 4.8 g Iriodin © 4504 0.1 g 7.0 g10:14 98.00 40.83 Lava Red (Merck KGaA) 77 1.5 g Iriodin © 9219 3.5 g7.0 g 10:14 30.00 12.50 (Merck KGaA) 78 1.0 g Iriodin © 9219 3.5 g 7.0 g 10:15.6 22.22 8.70 (Merck KGaA) 79 0.8 g Iriodin © 9219 3.5 g 7.0 g 10:16.3 18.60 7.08 (Merck KGaA) 80 0.6 g Iriodin © 9219 3.5 g 7.0 g 10:17.1 14.63 5.41 (Merck KGaA) 81 1.5 g Iriodin © 9219 3.5 g 9.0 g10:18 30.00 10.71 (Merck KGaA) 82 1.0 g Iriodin © 9219 3.5 g 9.0 g 10:2022.22 7.41 (Merck KGaA) 83 0.8 g Iriodin © 9219 3.5 g 9.0 g  10:20.918.60 6.02 (Merck KGaA) 84 0.6 g Iriodin © 9219 3.5 g 9.0 g 10:22 14.634.58 (Merck KGaA) 85 1.5 g Iriodin © 9219 2.0 g 7.0 g 10:20 42.86 14.29(Merck KGaA) 86 1.5 g Iriodin © 9219 1.5 g 7.0 g  10:23.3 50.00 15.00(Merck KGaA) 87 1.5 g Iriodin © 9219 1.0 g 7.0 g 10:28 60.00 15.79(Merck KGaA) 88 1.5 g Iriodin © 9219 0.5 g 7.0 g 10:35 75.00 16.67(Merck KGaA) 89 5.0 g Iriodin © 9219 0.0 g 7.0 g 10:14 100.0 41.67(Merck KGaA) 90 2.0 g Iriodin © 9219 3.0 g 7.0 g 10:14 40.00 16.67(Merck KGaA) 91 3.8 g Iriodin © 9219 1.2 g 7.0 g 10:14 76.00 31.67(Merck KGaA) 92 4.3 g Iriodin © 9219 0.7 g 7.0 g 10:14 86.00 35.83(Merck KGaA) 93 4.5 g Iriodin © 9219 0.5 g 7.0 g 10:14 90.00 37.50(Merck KGaA) 94 4.8 g Iriodin © 9219 0.2 g 7.0 g 10:14 96.00 40.00(Merck KGaA) 95 4.9 g Iriodin © 9219 0.1 g 7.0 g 10:14 98.00 40.83(Merck KGaA) 96 1.5 g Iriodin © 9444 3.5 g 7.0 g 10:14 30.00 12.50(Merck KGaA) 97 1.0 g Iriodin © 9444 3.5 g 7.0 g  10:15.6 22.22 8.70(Merck KGaA) 98 0.8 g Iriodin © 9444 3.5 g 7.0 g  10:16.3 18.60 7.08(Merck KGaA) 99 0.6 g Iriodin © 9444 3.5 g 7.0 g  10:17.1 14.63 5.41(Merck KGaA) 100 1.5 g Iriodin © 9444 3.5 g 9.0 g 10:18 30.00 10.71(Merck KGaA) 101 1.0 g Iriodin © 9444 3.5 g 9.0 g 10:20 22.22 7.41(Merck KGaA) 102 0.8 g Iriodin © 9444 3.5 g 9.0 g  10:20.9 18.60 6.02(Merck KGaA) 103 0.6 g Iriodin © 9444 3.5 g 9.0 g 10:22 14.63 4.58(Merck KGaA) 104 1.5 g Iriodin © 9444 2.0 g 7.0 g 10:20 42.86 14.29(Merck KGaA) 105 1.5 g Iriodin © 9444 1.5 g 7.0 g  10:23.3 50.00 15.00(Merck KGaA) 106 1.5 g Iriodin © 9444 1.0 g 7.0 g 10:28 60.00 15.79(Merck KGaA) 107 1.5 g Iriodin © 9444 0.5 g 7.0 g 10:35 75.00 16.67(Merck KGaA) 108 5.0 g Iriodin © 9444 0.0 g 7.0 g 10:14 100.0 41.67(Merck KGaA) 109 2.0 g Iriodin © 9444 3.0 g 7.0 g 10:14 40.00 16.67(Merck KGaA) 110 3.8 g Iriodin © 9444 1.2 g 7.0 g 10:14 76.00 31.67(Merck KGaA) 111 4.3 g Iriodin © 9444 0.7 g 7.0 g 10:14 86.00 35.83(Merck KGaA) 112 4.5 g Iriodin © 9444 0.5 g 7.0 g 10:14 90.00 37.50(Merck KGaA) 113 4.8 g Iriodin © 9444 0.2 g 7.0 g 10:14 96.00 40.00(Merck KGaA) 114 4.9 g Iriodin © 9444 0.1 g 7.0 g 10:14 98.00 40.83(Merck KGaA) 115 1.5 g Iriodin © 9504 3.5 g 7.0 g 10:14 30.00 12.50(Merck KGaA) 116 1.0 g Iriodin © 9504 3.5 g 7.0 g  10:15.6 22.22 8.70(Merck KGaA) 117 0.8 g Iriodin © 9504 3.5 g 7.0 g  10:16.3 18.60 7.08(Merck KGaA) 118 0.6 g Iriodin © 9504 3.5 g 7.0 g  10:17.1 14.63 5.41(Merck KGaA) 119 1.5 g Iriodin © 9504 3.5 g 9.0 g 10:18 30.00 10.71(Merck KGaA) 120 1.0 g Iriodin © 9504 3.5 g 9.0 g 10:20 22.22 7.41(Merck KGaA) 121 0.8 g Iriodin © 9504 3.5 g 9.0 g  10:20.9 18.60 6.02(Merck KGaA) 122 0.6 g Iriodin © 9504 3.5 g 9.0 g 10:22 14.63 4.58(Merck KGaA) 123 1.5 g Iriodin © 9504 2.0 g 7.0 g 10:20 42.86 14.29(Merck KGaA) 124 1.5 g Iriodin © 9504 1.5 g 7.0 g  10:23.3 50.00 15.00(Merck KGaA) 125 1.5 g Iriodin © 9504 1.0 g 7.0 g 10:28 60.00 15.79(Merck KGaA) 126 1.5 g Iriodin © 9504 0.5 g 7.0 g 10:35 75.00 16.67(Merck KGaA) 127 5.0 g Iriodin © 9504 0.0 g 7.0 g 10:14 100.0 41.67(Merck KGaA) 128 2.0 g Iriodin © 9504 3.0 g 7.0 g 10:14 40.00 16.67(Merck KGaA) 129 3.8 g Iriodin © 9504 1.2 g 7.0 g 10:14 76.00 31.67(Merck KGaA) 130 4.3 g Iriodin © 9504 0.7 g 7.0 g 10:14 86.00 35.83(Merck KGaA) 131 4.5 g Iriodin © 9504 0.5 g 7.0 g 10:14 90.00 37.50(Merck KGaA) 132 4.8 g Iriodin © 9504 0.2 g 7.0 g 10:14 96.00 40.00(Merck KGaA) 133 4.9 g Iriodin © 9504 0.1 g 7.0 g 10:14 98.00 40.83(Merck KGaA) 134 1.5 g Xirallic © F60-50 3.5 g 7.0 g 10:14 30.00 12.50(Merck KGaA) 135 1.0 g Xirallic © F60-50 3.5 g 7.0 g  10:15.6 22.22 8.70(Merck KGaA) 136 0.8 g Xirallic © F60-50 3.5 g 7.0 g  10:16.3 18.60 7.08(Merck KGaA) 137 0.6 g Xirallic © F60-50 3.5 g 7.0 g  10:17.1 14.63 5.41(Merck KGaA) 138 1.5 g Xirallic © F60-50 3.5 g 9.0 g 10:18 30.00 10.71(Merck KGaA) 139 1.0 g Xirallic © F60-50 3.5 g 9.0 g 10:20 22.22 7.41(Merck KGaA) 140 0.8 g Xirallic © F60-50 3.5 g 9.0 g  10:20.9 18.60 6.02(Merck KGaA) 141 0.6 g Xirallic © F60-50 3.5 g 9.0 g 10:22 14.63 4.58(Merck KGaA) 142 1.5 g Xirallic © F60-50 2.0 g 7.0 g 10:20 42.86 14.29(Merck KGaA) 143 1.5 g Xirallic © F60-50 1.5 g 7.0 g  10:23.3 50.0015.00 (Merck KGaA) 144 1.5 g Xirallic © F60-50 1.0 g 7.0 g 10:28 60.0015.79 (Merck KGaA) 145 1.5 g Xirallic © F60-50 0.5 g 7.0 g 10:35 75.0016.67 (Merck KGaA) 146 5.0 g Xirallic © F60-50 0.0 g 7.0 g 10:14 100.041.67 (Merck KGaA) 147 2.0 g Xirallic © F60-50 3.0 g 7.0 g 10:14 40.0016.67 (Merck KGaA) 148 3.8 g Xirallic © F60-50 1.2 g 7.0 g 10:14 76.0031.67 (Merck KGaA) 149 4.3 g Xirallic © F60-50 0.7 g 7.0 g 10:14 86.0035.83 (Merck KGaA) 150 4.5 g Xirallic © F60-50 0.5 g 7.0 g 10:14 90.0037.50 (Merck KGaA) 151 4.8 g Xirallic © F60-50 0.2 g 7.0 g 10:14 96.0040.00 (Merck KGaA) 152 4.9 g Xirallic © F60-50 0.1 g 7.0 g 10:14 98.0040.83 (Merck KGaA) 153 1.5 g Xirallic © F60-51 3.5 g 7.0 g 10:14 30.0012.50 (Merck KGaA) 154 1.0 g Xirallic © F60-51 3.5 g 7.0 g  10:15.622.22 8.70 (Merck KGaA) 155 0.8 g Xirallic © F60-51 3.5 g 7.0 g  10:16.318.60 7.08 (Merck KGaA) 156 0.6 g Xirallic © F60-51 3.5 g 7.0 g  10:17.114.63 5.41 (Merck KGaA) 157 1.5 g Xirallic © F60-51 3.5 g 9.0 g 10:1830.00 10.71 (Merck KGaA) 158 1.0 g Xirallic © F60-51 3.5 g 9.0 g 10:2022.22 7.41 (Merck KGaA) 159 0.8 g Xirallic © F60-51 3.5 g 9.0 g  10:20.918.60 6.02 (Merck KGaA) 160 0.6 g Xirallic © F60-51 3.5 g 9.0 g 10:2214.63 4.58 (Merck KGaA) 161 1.5 g Xirallic © F60-51 2.0 g 7.0 g 10:2042.86 14.29 (Merck KGaA) 162 1.5 g Xirallic © F60-51 1.5 g 7.0 g 10:23.3 50.00 15.00 (Merck KGaA) 163 1.5 g Xirallic © F60-51 1.0 g 7.0g 10:28 60.00 15.79 (Merck KGaA) 164 1.5 g Xirallic © F60-51 0.5 g 7.0 g10:35 75.00 16.67 (Merck KGaA) 165 5.0 g Xirallic © F60-51 0.0 g 7.0 g10:14 100.0 41.67 (Merck KGaA) 166 2.0 g Xirallic © F60-51 3.0 g 7.0 g10:14 40.00 16.67 (Merck KGaA) 167 3.8 g Xirallic © F60-51 1.2 g 7.0 g10:14 76.00 31.67 (Merck KGaA) 168 4.3 g Xirallic © F60-51 0.7 g 7.0 g10:14 86.00 35.83 (Merck KGaA) 169 4.5 g Xirallic © F60-51 0.5 g 7.0 g10:14 90.00 37.50 (Merck KGaA) 170 4.8 g Xirallic © F60-51 0.2 g 7.0 g10:14 96.00 40.00 (Merck KGaA) 171 4.9 g Xirallic © F60-51 0.1 g 7.0 g10:14 98.00 40.83 (Merck KGaA) 172 1.5 g Pyrisma © M40-58 3.5 g 7.0 g10:14 30.00 12.50 (Merck KGaA) 173 1.0 g Pyrisma © M40-58 3.5 g 7.0 g 10:15.6 22.22 8.70 (Merck KGaA) 174 0.8 g Pyrisma © M40-58 3.5 g 7.0 g 10:16.3 18.60 7.08 (Merck KGaA) 175 0.6 g Pyrisma © M40-58 3.5 g 7.0 g 10:17.1 14.63 5.41 (Merck KGaA) 176 1.5 g Pyrisma © M40-58 3.5 g 9.0 g10:18 30.00 10.71 (Merck KGaA) 177 1.0 g Pyrisma © M40-58 3.5 g 9.0 g10:20 22.22 7.41 (Merck KGaA) 178 0.8 g Pyrisma © M40-58 3.5 g 9.0 g 10:20.9 18.60 6.02 (Merck KGaA) 179 0.6 g Pyrisma © M40-58 3.5 g 9.0 g10:22 14.63 4.58 (Merck KGaA) 180 1.5 g Pyrisma © M40-58 2.0 g 7.0 g10:20 42.86 14.29 (Merck KGaA) 181 1.5 g Pyrisma © M40-58 1.5 g 7.0 g 10:23.3 50.00 15.00 (Merck KGaA) 182 1.5 g Pyrisma © M40-58 1.0 g 7.0 g10:28 60.00 15.79 (Merck KGaA) 183 1.5 g Pyrisma © M40-58 0.5 g 7.0 g10:35 75.00 16.67 (Merck KGaA) 184 5.0 g Pyrisma © M40-58 0.0 g 7.0 g10:14 100.0 41.67 (Merck KGaA) 185 2.0 g Pyrisma © M40-58 3.0 g 7.0 g10:14 40.00 16.67 (Merck KGaA) 186 3.8 g Pyrisma © M40-58 1.2 g 7.0 g10:14 76.00 31.67 (Merck KGaA) 187 4.3 g Pyrisma © M40-58 0.7 g 7.0 g10:14 86.00 35.83 (Merck KGaA) 188 4.5 g Pyrisma © M40-58 0.5 g 7.0 g10:14 90.00 37.50 (Merck KGaA) 189 4.8 g Pyrisma © M40-58 0.2 g 7.0 g10:14 96.00 40.00 (Merck KGaA) 190 4.9 g Pyrisma © M40-58 0.1 g 7.0 g10:14 98.00 40.83 (Merck KGaA) 191 4.3 g SynCrystal © Silver 0.7 g 7.0 g10:14 86.00 35.83 (Eckart GmbH) 192 4.5 g SYMIC © B001 0.5 g 7.0 g 10:1490.00 37.50 Silver (Eckart GmbH) 193 1.5 g SYMIC © C001 1.0 g 7.0 g10:28 60.00 15.79 Silver (Eckart GmbH) 194 1.5 g SYMIC © C604 2.0 g 7.0g 10:20 42.86 14.29 Silver (Eckart GmbH) 195 1.5 g SYMIC © OEM 2.0 g 7.0g 10:20 42.86 14.29 X-fine Silver (Eckart GmbH) 196 1.5 g SYMIC © C3932.0 g 7.0 g 10:20 42.86 14.29 Gold (Eckart GmbH) 197 4.3 g SYMIC © C5220.7 g 7.0 g 10:14 86.00 35.83 Copper Earth Shade (Eckart GmbH) 198 4.3 gSYMIC © C542 Fire 0.7 g 7.0 g 10:14 86.00 35.83 Red Earth Shade (EckartGmbH) 199 4.3 g SYMIC © OEM 0.7 g 7.0 g 10:14 86.00 35.83 Medium SpaceGold (Eckart GmbH) 200 1.5 g Magnapearl © 2.0 g 7.0 g 10:20 42.86 14.291000 (BASF AG) 201 1.5 g Magnapearl © 1.0 g 7.0 g 10:28 60.00 15.79 2000(BASF AG) 202 3.8 g Magnapearl © 1.2 g 7.0 g 10:14 76.00 31.67 3100(BASF AG) 203 1.5 g Lumina © Brass 2.0 g 7.0 g 10:20 42.86 14.29 9232D(BASF AG) 204 1.5 g Lumina © Copper 1.0 g 7.0 g 10:28 60.00 15.79 9350D(BASF AG) 205 3.8 g Lumina © Exterior 1.2 g 7.0 g 10:14 76.00 31.67 Gold2303D (BASF AG) 206 4.3 g Lumina © Russet 0.7 g 7.0 g 10:14 86.00 35.839450D (BASF AG) 207 1.5 g Lumina © Royal 2.0 g 7.0 g 10:20 42.86 14.29Copper (BASF AG) 208 1.5 g Lumina © Royal 1.5 g 7.0 g  10:23.3 50.0015.00 Magenta (BASF AG) 209 1.5 g Lumina © Royal 1.0 g 7.0 g 10:28 60.0015.79 Blue (BASF AG) 210 1.5 g Exterior Polar 2.0 g 7.0 g 10:20 42.8614.29 White KC9119-SW (Fujian Kuncai Fine Chemicals Co., Ltd.) 211 1.5 gExterior Sterling 1.0 g 7.0 g 10:28 60.00 15.79 White KC9103-SW (FujianKuncai Fine Chemicals Co., Ltd.) 212 1.5 g Exterior Fine Gold 1.0 g 7.0g 10:28 60.00 15.79 Satin KC9201-SW (Fujian Kuncai Fine Chemicals Co.,Ltd.) 213 1.5 g Exterior Platinum 1.0 g 7.0 g 10:28 60.00 15.79 PearlKC9205-SW (Fujian Kuncai Fine Chemicals Co., Ltd.) 214 1.5 g ExteriorGold 1.0 g 7.0 g 10:28 60.00 15.79 Pearl KC9300-SW (Fujian Kuncai FineChemicals Co., Ltd.) 215 1.5 g Exterior Royal 1.0 g 7.0 g 10:28 60.0015.79 Gold KC9303-SW (Fujian Kuncai Fine Chemicals Co., Ltd.) 216 3.8 gExterior Royal 1.2 g 7.0 g 10:14 76.00 31.67 Gold Satin KC9323-SW(Fujian Kuncai Fine Chemicals Co., Ltd.) 217 3.8 g Exterior Bright 1.2 g7.0 g 10:14 76.00 31.67 Gold KC9307-SW (Fujian Kuncai Fine ChemicalsCo., Ltd.) 218 3.8 g Exterior Bronze 1.2 g 7.0 g 10:14 76.00 31.67KC9502-SW (Fujian Kuncai Fine Chemicals Co., Ltd.) 219 4.3 g ExteriorWine Red 0.7 g 7.0 g 10:14 86.00 35.83 KC9504-SW (Fujian Kuncai FineChemicals Co., Ltd.) 220 4.3 g Exterior Ruby 0.7 g 7.0 g 10:14 86.0035.83 KC9508-SW (Fujian Kuncai Fine Chemicals Co., Ltd.) 221 1.5 gADAMAS © A-100D 2.0 g 7.0 g 10:20 42.86 14.29 (CQV Co., Ltd) 222 1.5 gADAMAS © A-100D 1.5 g 7.0 g  10:23.3 50.00 15.00 (CQV Co., Ltd) 223 1.5g ADAMAS © A-100D 1.0 g 7.0 g 10:28 60.00 15.79 (CQV Co., Ltd) 224 3.8 gADAMAS © A-100D 1.2 g 7.0 g 10:14 76.00 31.67 (CQV Co., Ltd) 225 4.3 gADAMAS © A-100D 0.7 g 7.0 g 10:14 86.00 35.83 (CQV Co., Ltd) 226 4.5 gADAMAS © A-100D 0.5 g 7.0 g 10:14 90.00 37.50 (CQV Co., Ltd) 227 3.8 gADAMAS © A-901K 1.2 g 7.0 g 10:14 76.00 31.67 Splendor White (CQV Co.,Ltd) 228 1.5 g ADAMAS © A-901S 2.0 g 7.0 g 10:20 42.86 14.29 DazzlingWhite (CQV Co., Ltd) 229 1.5 g ADAMAS © A-901S 1.0 g 7.0 g 10:28 60.0015.79 Dazzling White (CQV Co., Ltd) 230 4.5 g ADAMAS © A-901S 0.5 g 7.0g 10:14 90.00 37.50 Dazzling White (CQV Co., Ltd) 231 1.5 g ADAMAS ©A-901K 2.0 g 7.0 g 10:20 42.86 14.29 Splendor Gold (CQV Co., Ltd) 2321.5 g ADAMAS © A-901K 1.0 g 7.0 g 10:28 60.00 15.79 Splendor Gold (CQVCo., Ltd) 233 4.5 g ADAMAS © A-901K 0.5 g 7.0 g 10:14 90.00 37.50Splendor Gold (CQV Co., Ltd) 234 1.5 g ADAMAS © 2.0 g 7.0 g 10:20 42.8614.29 A-701S Dazzling Gold (CQV Co., Ltd) 235 1.5 g ADAMAS © A-701S 1.0g 7.0 g 10:28 60.00 15.79 Dazzling Gold (CQV Co., Ltd) 236 4.5 gADAMAS © A-701S 0.5 g 7.0 g 10:14 90.00 37.50 Dazzling Gold (CQV Co.,Ltd) 237 1.5 g ADAMAS © A-741S 1.0 g 7.0 g 10:28 60.00 15.79 DazzlingRed (CQV Co., Ltd) 238 1.5 g ADAMAS © A-781K 1.0 g 7.0 g 10:28 60.0015.79 Splendor Blue (CQV Co., Ltd) 239 1.5 g ADAMAS © A-781S 1.0 g 7.0 g10:28 60.00 15.79 Dazzling Blue (CQV Co., Ltd) 240 1.5 g ADAMAS © A-620S2.0 g 7.0 g 10:20 42.86 14.29 Dazzling Bronze (CQV Co., Ltd) 241 1.5 gADAMAS © A-620S 1.0 g 7.0 g 10:28 60.00 15.79 Dazzling Bronze (CQV Co.,Ltd) 242 4.5 g ADAMAS © A-620S 0.5 g 7.0 g 10:14 90.00 37.50 DazzlingBronze (CQV Co., Ltd) 243 1.5 g ADAMAS © A-640K 2.0 g 7.0 g 10:20 42.8614.29 Splendor Copper (CQV Co., Ltd) 244 1.5 g ADAMAS © A-640K 1.0 g 7.0g 10:28 60.00 15.79 Splendor Copper (CQV Co., Ltd) 245 4.5 g ADAMAS ©A-640K 0.5 g 7.0 g 10:14 90.00 37.50 Splendor Copper (CQV Co., Ltd) 2461.5 g ADAMAS © A-640S 2.0 g 7.0 g 10:20 42.86 14.29 Dazzling Copper (CQVCo., Ltd) 247 1.5 g ADAMAS © A-640S 1.0 g 7.0 g 10:28 60.00 15.79Dazzling Copper (CQV Co., Ltd) 248 4.5 g ADAMAS © A-640S 0.5 g 7.0 g10:14 90.00 37.50 Dazzling Copper (CQV Co., Ltd) 249 1.5 g ADAMAS ©A-660K 2.0 g 7.0 g 10:20 42.86 14.29 Splendor Russet (CQV Co., Ltd) 2501.5 g ADAMAS © A-660K 1.0 g 7.0 g 10:28 60.00 15.79 Splendor Russet (CQVCo., Ltd) 251 4.5 g ADAMAS © A-660K 0.5 g 7.0 g 10:14 90.00 37.50Splendor Russet (CQV Co., Ltd) 252 3.8 g ADAMAS © A-660S 1.2 g 7.0 g10:14 76.00 31.67 Dazzling Russet (CQV Co., Ltd) 253 3.8 g CHAOS ©C-901M 1.2 g 7.0 g 10:14 76.00 31.67 Rutile Ultra Silk (CQV Co., Ltd)254 3.8 g CHAOS © C-901D 1.2 g 7.0 g 10:14 76.00 31.67 Rutile Fine White(CQV Co., Ltd) 255 3.8 g CHAOS © C-900D 1.2 g 7.0 g 10:14 76.00 31.67Fine White (CQV Co., Ltd) 256 3.8 g CHAOS © C-907K 1.2 g 7.0 g 10:1476.00 31.67 Skye White (CQV Co., Ltd) 257 3.8 g CHAOS © C-901K 1.2 g 7.0g 10:14 76.00 31.67 Splendor White (CQV Co., Ltd) 258 3.8 g CHAOS ©C-901S 1.2 g 7.0 g 10:14 76.00 31.67 Rutile Dazzling Standard (CQV Co.,Ltd) 259 3.8 g CHAOS © C-900S 1.2 g 7.0 g 10:14 76.00 31.67 DazzlingStandard (CQV Co., Ltd) 260 1.5 g CHAOS © C-902S 1.0 g 7.0 g 10:28 60.0015.79 Super White (CQV Co., Ltd) 261 1.5 g CHAOS © C-109S 1.0 g 7.0 g10:28 60.00 15.79 Super Pearl (CQV Co., Ltd) 262 1.5 g CHAOS © C-109B1.0 g 7.0 g 10:28 60.00 15.79 Shimmering White (CQV Co., Ltd) 263 1.5 gCHAOS © C-901E 1.0 g 7.0 g 10:28 60.00 15.79 Glitter Pearl (CQV Co.,Ltd) 264 1.5 g FERRIUS © F-620K 2.0 g 7.0 g 10:20 42.86 14.29 SplendorBronze (CQV Co., Ltd) 265 1.5 g FERRIUS © F-630K 1.0 g 7.0 g 10:28 60.0015.79 Splendor Orange (CQV Co., Ltd) 266 4.5 g FERRIUS © F-640K 0.5 g7.0 g 10:14 90.00 37.50 Splendor Copper (CQV Co., Ltd) 267 1.5 gFERRIUS © F-660K 2.0 g 7.0 g 10:20 42.86 14.29 Splendor Russet (CQV Co.,Ltd) 268 1.5 g FERRIUS © F-620P 1.0 g 7.0 g 10:28 60.00 15.79 CrystalBronze (CQV Co., Ltd) 269 4.5 g FERRIUS © F-630P 0.5 g 7.0 g 10:14 90.0037.50 Crystal Orange (CQV Co., Ltd) 270 1.5 g FERRIUS © F-640P 2.0 g 7.0g 10:20 42.86 14.29 Crystal Copper (CQV Co., Ltd) 271 1.5 g FERRIUS ©F-660P 1.0 g 7.0 g 10:28 60.00 15.79 Crystal Russet (CQV Co., Ltd) 2723.8 g Magchrom © 1.2 g 7.0 g 10:14 76.00 31.67 N-5001C Natural CoronaGold (CQV Co., Ltd) 273 3.8 g Magchrom © 1.2 g 7.0 g 10:14 76.00 31.67N-5001S Natural Dazzling Gold (CQV Co., Ltd) 274 3.8 g Magchrom © 1.2 g7.0 g 10:14 76.00 31.67 S-7801C Corona Blue (CQV Co., Ltd) 275 3.8 gREFLEX © RCN- 1.2 g 7.0 g 10:14 76.00 31.67 1008S Snow White Pearl (CQVCo., Ltd)

The pearlescent pigments used in the table are all commerciallyavailable and have the following composition (in the “Particle size”column, the d₁₀-d₉₀ value is measured using a Malvern is indicated ineach case):

Particle Manufac- size Trade name turer Substrate Coating [μm]Xirallic © Crystal Merck KGaA Al₂O₃ TiO₂ 5-35 Silver Iriodin © 103 MerckKGaA Natural TiO₂ 10-60  mica Iriodin © 305 Merck KGaA Natural Fe₂O₃10-60  mica and TiO₂ Iriodin © 4504 Merck KGaA SiO₂ Fe₂O₃ 5-50 Lava RedIriodin © 9219 Merck KGaA Natural TiO₂ 10-60  mica Iriodin © 9444 MerckKGaA Natural Cr₂O₃ 5-40 mica Iriodin © 9504 Merck KGaA Natural Fe₂O₃10-60  mica Xirallic © F60-50 Merck KGaA Al₂O₃ Fe₂O₃ 5-35 Xirallic ©F60-51 Merck KGaA Al₂O₃ Fe₂O₃ 5-35 Pyrisma © M40-58 Merck KGaA NaturalFe₂O₃ 5-40 mica and TiO₂ SynCrystal © Silver Eckart GmbH Synthetic TiO₂10-50  mica SYMIC © B001 Silver Eckart GmbH Synthetic TiO₂ 5-25 micaSYMIC © C001 Silver Eckart GmbH Synthetic TiO₂ 10-40  mica SYMIC © C604Silver Eckart GmbH Synthetic TiO₂ 10-40  mica SYMIC © OEM X-fine EckartGmbH Synthetic TiO₂ 3-15 Silver mica SYMIC © C393 Gold Eckart GmbHSynthetic Fe₂O₃ 10-40  mica and TiO₂ SYMIC © C522 Eckart GmbH SyntheticFe₂O₃ 10-40  Copper Earth Shade mica SYMIC © C542 Fire Eckart GmbHSynthetic Fe₂O₃ 10-40  Red Earth Shade mica SYMIC © OEM Eckart GmbHSynthetic Fe₂O₃ 12-38  Medium Space Gold mica and TiO₂ Magnapearl © 1000BASF AG Natural TiO₂ 6-48 mica Magnapearl © 2000 BASF AG Natural TiO₂5-25 mica Magnapearl © 3100 BASF AG Natural TiO₂ 2-10 mica Lumina ©Brass BASF AG Natural Fe₂O₃ 10-48  9232D mica and TiO₂ Lumina © CopperBASF AG Natural Fe₂O₃ 8-48 9350D mica Lumina © Exterior BASF AG NaturalTiO₂ 8-48 Gold 2303D mica Lumina © Russet BASF AG Natural Fe₂O₃ 8-489450D mica Lumina © Royal BASF AG Natural TiO₂ 10-34  Copper micaLumina © Royal BASF AG Natural TiO₂ 10-34  Magenta mica Lumina © RoyalBlue BASF AG Natural TiO₂ 10-34  mica Exterior Polar White Fujian KuncaiNatural TiO₂ 5-25 KC9119-SW Fine Chemi- mica cals Co., Ltd. ExteriorSterling Fujian Kuncai Natural TiO₂ 10-45  White KC9103-SW Fine Chemi-mica cals Co., Ltd. Exterior Fine Gold Fujian Kuncai Natural TiO₂ 5-25Satin KC9201-SW Fine Chemi- mica cals Co., Ltd. Exterior Platinum FujianKuncai Natural TiO₂ 10-45  Pearl KC9205-SW Fine Chemi- mica cals Co.,Ltd. Exterior Royal Gold Fujian Kuncai Natural Fe₂O₃ 10-45  KC9303-SWFine Chemi- mica and cals Co., Ltd. TiO₂ Exterior Royal Gold FujianKuncai Natural Fe₂O₃ 5-25 Satin KC9323-SW Fine Chemi- mica and cals Co.,Ltd. TiO₂ Exterior Bright Gold Fujian Kuncai Natural Fe₂O₃ 10-60 KC9307-SW Fine Chemi- mica and cals Co., Ltd. TiO₂ Exterior Brown FujianKuncai Natural Fe₂O₃ 8-45 KC9502-SW Fine Chemi- mica cals Co., Ltd.Exterior Wine Red Fujian Kuncai Natural Fe₂O₃ 8-45 KC9504-SW Fine Chemi-mica cals Co., Ltd. Exterior Ruby Fujian Kuncai Natural Fe₂O₃ 8-45KC9508-SW Fine Chemi- mica cals Co., Ltd. ADAMAS © A-100D CQV Co., Ltd.Al₂O₃ TiO₂ 3-30 ADAMAS © A-901K CQV Co., Ltd. Al₂O₃ TiO₂ 5-30 SplendorWhite ADAMAS © A-901S CQV Co., Ltd. Al₂O₃ TiO₂ 9-45 Dazzling WhiteADAMAS © A-901K CQV Co., Ltd. Al₂O₃ TiO₂ 5-30 Splendor Gold ADAMAS ©A-701S CQV Co., Ltd. Al₂O₃ TiO₂ 9-45 Dazzling Gold ADAMAS © A-741S CQVCo., Ltd. Al₂O₃ TiO₂ 9-45 Dazzling Red ADAMAS © A-781K CQV Co., Ltd.Al₂O₃ TiO₂ 5-30 Splendor Blue ADAMAS © A-781S CQV Co., Ltd. Al₂O₃ TiO₂9-45 Dazzling Blue ADAMAS © A-620S CQV Co., Ltd. Al₂O₃ Fe₂O₃ 9-45Dazzling Bronze ADAMAS © A-640S CQV Co., Ltd. Al₂O₃ Fe₂O₃ 9-45 DazzlingCopper ADAMAS © A-660S CQV Co., Ltd. Al₂O₃ Fe₂O₃ 9-45 Dazzling RussetCHAOS © C-901M CQV Co., Ltd. Synthetic TiO₂ 3-17 Rutile Ultra Silk micaCHAOS © C-901D CQV Co., Ltd. Synthetic TiO₂ 5-25 Rutile Fine White micaCHAOS © C-900D CQV Co., Ltd. Synthetic TiO₂ 5-25 Fine White mica CHAOS ©C-907K CQV Co., Ltd. Synthetic TiO₂ 5-35 Sky White mica CHAOS © C-901KCQV Co., Ltd. Synthetic TiO₂ 5-35 Splendor White mica CHAOS © C-901S CQVCo., Ltd. Synthetic TiO₂ 9-45 Rutile Dazzling mica Standard CHAOS ©C-900S CQV Co., Ltd. Synthetic TiO₂ 9-45 Dazzling Standard mica CHAOS ©C-902S CQV Co., Ltd. Synthetic TiO₂ 9-45 Super White mica CHAOS © C-109SCQV Co., Ltd. Synthetic TiO₂ 9-41 Super Pearl mica CHAOS © C-109B CQVCo., Ltd. Synthetic TiO₂ 13-60  Shimmering White mica CHAOS © C-901E CQVCo., Ltd. Synthetic TiO₂ 17-100 Glitter Pearl mica FERRIUS © F-620K CQVCo., Ltd. Synthetic Fe₂O₃ 5-35 Splendor Bronze mica FERRIUS © F-630K CQVCo., Ltd. Synthetic Fe₂O₃ 5-35 Splendor Orange mica FERRIUS © F-640K CQVCo., Ltd. Synthetic Fe₂O₃ 5-35 Splendor Copper mica FERRIUS © F-660K CQVCo., Ltd. Synthetic Fe₂O₃ 5-35 Splendor Russet mica FERRIUS © F-620P CQVCo., Ltd. Synthetic Fe₂O₃ 25-150 Crystal Bronze mica FERRIUS © F-630PCQV Co., Ltd. Synthetic Fe₂O₃ 25-150 Crystal Orange mica FERRIUS ©F-640P CQV Co., Ltd. Synthetic Fe₂O₃ 25-150 Crystal Copper micaFERRIUS © F-660P CQV Co., Ltd. Synthetic Fe₂O₃ 25-150 Crystal Russetmica Magchrom © N-5001C CQV Co., Ltd. Nat. mica TiO₂ 7-30 Natural CoronaGold Magchrom © N-5001S CQV Co., Ltd. Nat. mica TiO₂ 9-45 NaturalDazzling Gold Magchrom © S-7801C CQV Co., Ltd. Synthetic TiO₂ 7-27Corona Blue mica

The following steps 2-4 are independent of the composition of theprinting paste.

2) Printing of the Tiles

The printing paste obtained can be applied to tiles by standard printingprocesses, slip processes, spray application or transfer printing. Inall cases, the printed tile is dried in a drying cabinet or fume hood attemperatures of 60-110° C. in order to evaporate the solvent present inthe printing oil. In the examples according to the invention, theprinting paste is applied to the tiles by means of doctor blade andscreen printing.

3) Firing of the Printed Tiles

The printed and dried tiles are then fired in a firing furnace by meansof a temperature profile in accordance with FIG. 6.

-   180 min: heating to 1100° C.,-   3 min: holding at 1100° C.,-   120 min: rapid cooling to 600° C.,-   300 min: slow cooling to room temperature.

The temperature program as a function of time is depicted in FIG. 6.

The glazed tiles of Examples 1 to 275 are distinguished by the fact thatthe desired optical effects are stable and accessible in a reproduciblemanner in high-temperature applications >1100° C.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show sectional side views through a pigmented frit layerbefore the firing operation, the particles of the frit are representedas round or oval particles and the pearlescent pigments are representedas rods.

FIGS. 3-5 diagrammatically show the plane-parallel alignment of thepearlescent pigments in the glaze.

FIG. 6 shows the temperature profile used for firing the printed anddried tiles in the Examples.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention and, withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

The invention claimed is:
 1. A pigment/frit mixture, comprising amixture of a pearlescent pigment and a frit in the form of particles,wherein the proportion of pearlescent pigment in the mixture is 5-95% byweight and the frit comprises at least 5% by weight of Al₂O₃, based onthe weight of the frit, wherein the pearlescent pigment is based on aflake substrate and the ratio of the thickness of the flake substrate tothe size of the frit particles is from 0.01 to 0.2.
 2. The pigment/fritmixture according to claim 1, wherein the flake substrate is selectedfrom: synthetic mica flakes, natural mica flakes, Al₂O₃ flakes, SiO₂flakes, Fe₂O₃ flakes, B₄C flakes, TiO₂ flakes, SiC flakes, BN flakes andgraphite flakes.
 3. The pigment/frit mixture according to claim 1,wherein the flake substrate is covered with one or more layers of metaloxide(s), metal sulfides, rare-earth metal oxides and/or metal(s) ormixtures thereof.
 4. The pigment/frit mixture according to claim 3,wherein the flake substrate is covered on the surface with one or morelayers selected from: TiO₂, Fe₂O₃, ZrO₂, SnO₂, TiO₂/Fe₂O₃, Fe₂TiO₅,FeTiO₃, FeOOH, Fe₃O₄, Cr₂O₃ and TiO_(x), where x=1.50-1.95.
 5. Thepigment/frit mixture according to claim 1, wherein the flake substratehas a particle thickness of 0.05-5.0 μm.
 6. The pigment/frit mixtureaccording to claim 1, wherein the frit has a particle size of 1-500 μm.7. The pigment/frit mixture according to claim 1, wherein the fritcomprises CaO, Na₂O, K₂O, BaO, SiO₂ or B₂O₃.
 8. The pigment/frit mixtureaccording to claim 1, wherein the frit comprises ≥5% by weight of Al₂O₃and ≥50% by weight of SiO₂, based on the weight of the frit, where thetotality of all constituents of the frit is 100%.
 9. The pigment/fritmixture according to claim 1, wherein the pearlescent pigment isselected from pigments having one of the following combinations ofsubstrate and layer(s) thereon: substrate flake+TiO₂; substrateflake+Fe₂O₃; substrate flake+Fe₃O₄; substrate flake+TiO₂/Fe₂O₃ substrateflake+FeTiO₃; substrate flake+Fe₂TiO₅ substrate flake+ZrO₂; substrateflake+ZnO; substrate flake+SnO₂; substrate flake+Cr₂O₃; substrateflake+Ce₂O₃; substrate flake+TiO_(x) (reduced), where x=1.50-1.95;substrate flake+TiO₂+Fe₂O₃; substrate flake+TiO₂+Fe₃O₄; substrateflake+Fe₂O₃+TiO₂; substrate flake+TiO₂+SiO₂+TiO₂; substrateflake+TiO₂+SnO₂+TiO₂; substrate flake+TiO₂+Al₂O₃+TiO₂; substrateflake+Fe₂O₃+SiO₂+TiO₂; substrate flake+TiO₂/Fe₂O₃+SiO₂+TiO₂; substrateflake+TiO₂/Fe₂O₃+SiO₂+TiO₂/Fe₂O₃; substrateflake+TiO₂/Fe₂O₃+SiO₂+TiO₂+TiO₂/Fe₂O₃; substrateflake+TiO₂+SiO₂+TiO₂/Fe₂O₃; substrate flake+TiO₂+SiO₂; substrateflake+TiO₂+Al₂O₃; substrate flake+TiO₂+MgO×SiO₂+TiO₂; substrateflake+Fe₂O₃+MgO×SiO₂+TiO₂; substrate flake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂;substrate flake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂/Fe₂O₃; substrateflake+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂+TiO₂/Fe₂O₃; substrateflake+TiO₂+MgO×SiO₂+TiO₂/Fe₂O₃; substrateflake+SnO₂+TiO₂+SiO₂+SnO₂+TiO₂; substrate flake+SnO₂+TiO₂+SnO₂+TiO₂;substrate flake+SnO₂+TiO₂+Fe₂O₃+SiO₂+SnO₂+TiO₂+Fe₂O₃; substrateflake+Fe₂O₃+SnO₂+TiO₂; substrate flake+Fe₂O₃+SnO₂+Fe₂O₃; substrateflake+TiO₂+SnO₂+TiO₂; substrate flake+TiO₂/Fe₂O₃+SnO₂+TiO₂; substrateflake+TiO₂/Fe₂O₃+SnO₂+TiO₂/Fe₂O₃; substrateflake+SnO₂+TiO₂+Fe₂O₃+SnO₂+TiO₂+Fe₂O₃; substrateflake+Fe₂TiO₅+SnO₂+Fe₂TiO₅; substrate flake+Fe₂TiO₅+SiO₂+Fe₂TiO₅. 10.The pigment/frit mixture according to claim 1, wherein the pearlescentpigment is on a flake substrate and has a first low-refractive-indexlayer (=LRL) on the flake substrate comprising Al₂O₃, SiO₂, zirconiumsilicate ZrSiO₄, mullite 3Al₂O₃×2SiO₂ or 2Al₂O₃×SiO₂ (sintered or fusedmullite) or alkaline-earth metal silicate (MSiO₃, where M=Mg²⁺, Ca²⁺,Sr²⁺or Ba²⁺, or M₂Si₃O₈, where M=Mg²⁺, Ca²⁺, Sr²⁺or Ba²⁺).
 11. Thepigment/frit mixture according to claim 10, wherein the pearlescentpigment is selected from pigments having one of the followingcombinations of substrate and layer(s) thereon: substrateflake+LRL+TiO₂; substrate flake+LRL+Fe₂O₃; substrate flake+LRL+Fe₃O₄;substrate flake+LRL+TiO₂/Fe₂O₃; substrate flake+LRL+FeTiO₃; substrateflake+LRL+Fe₂TiO₅; substrate flake+LRL+ZrO₂; substrate flake+LRL+ZnO;substrate flake+LRL+SnO₂; substrate flake+LRL+Cr₂O₃; substrateflake+LRL+Ce₂O₃; substrate flake+LRL+TiO_(x) (reduced), wherex=1.50-1.95; substrate flake+LRL+TiO₂+Fe₂O₃; substrateflake+LRL+TiO₂+Fe₃O₄; substrate flake+LRL+Fe₂O₃+TiO₂; substrateflake+LRL+TiO₂+SiO₂+TiO₂; substrate flake+LRL+TiO₂+SnO₂+TiO₂; substrateflake+LRL+TiO₂+Al₂O₃+TiO₂; substrate flake+LRL+Fe₂O₃+SiO₂+TiO₂;substrate flake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂; substrateflake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂/Fe₂O₃; substrateflake+LRL+TiO₂/Fe₂O₃+SiO₂+TiO₂+TiO₂/Fe₂O₃; substrateflake+LRL+TiO₂+SiO₂+TiO₂/Fe₂O₃; substrate flake+LRL+TiO₂+SiO₂; substrateflake+LRL+TiO₂+Al₂O₃; substrate flake+LRL+TiO₂+MgO×SiO₂+TiO₂; substrateflake+LRL+Fe₂O₃+MgO×SiO₂+TiO₂; substrateflake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂; substrateflake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂/Fe₂O₃; substrateflake+LRL+TiO₂/Fe₂O₃+MgO×SiO₂+TiO₂+TiO₂/Fe₂O₃; substrateflake+LRL+TiO₂+MgO×SiO₂+TiO₂/Fe₂O₃; substrateflake+LRL+SnO₂+TiO₂+SiO₂+SnO₂+TiO₂; substrateflake+LRL+SnO₂+TiO₂+SnO₂+TiO₂; substrateflake+LRL+SnO₂+TiO₂+Fe₂O₃+SiO₂+SnO₂+TiO₂+Fe₂O₃; substrateflake+LRL+Fe₂O₃+SnO₂+TiO₂; substrate flake+LRL+Fe₂O₃+SnO₂+Fe₂O₃;substrate flake+LRL+TiO₂+SnO₂+TiO₂; substrateflake+LRL+TiO₂/Fe₂O₃+SnO₂+TiO₂; substrateflake+LRL+TiO₂/Fe₂O₃+SnO₂+TiO₂/Fe₂O₃; substrateflake+LRL+SnO₂+TiO₂+Fe₂O₃+SnO₂+TiO₂+Fe₂O₃; substrateflake+LRL+Fe₂TiO₅+SnO₂+Fe₂TiO₅; substrateflake+LRL+Fe₂TiO₅+SiO₂+Fe₂TiO₅.
 12. An unfired or fired brick, unfiredor fired earthenware, unfired or fired ceramicware or a ceramic glaze,which comprises a pigment/frit mixture according to claim
 1. 13. Adecorative tile, which comprises a pigment/frit mixture according toclaim
 1. 14. A porcelain glaze, which comprises a pigment/frit mixtureaccording to claim
 1. 15. A composition comprising the pigment/fritmixture according to claim 1 and a dispersant, binder and/or printingoil.
 16. A method of making an article which is an unfired or firedbrick, unfired or fired earthenware, unfired or fired ceramicware or aceramic glaze, wherein the article is prepared by firing it to atemperature above 1000° C., wherein, before firing, a pigment/fritmixture according to claim 1 is incorporated into a composition used toprepare the article.
 17. The method of claim 16, wherein the article isa decorative tile.
 18. The method of claim 16, wherein the article is aporcelain glaze.
 19. The pigment/frit mixture according to claim 1,wherein the Al₂O₃ content in the frit is ≥7% by weight based on theweight of the frit.